Internal-combustion engine



F. H. GILE.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JUNE 2.7. I9I8.

Patented Mar. 30, 1920.

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r a:15.2%;n? I 4 F. Hi GILE.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED JUNE 27, 1918.

Patented Mar. 30, 1920.

2 SHEETS-SHEET 2- UNITED STATES PATENT OFFICE.

FRED HENRY GILE, OF CLIFTONDALE, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO GEORGE K. WOODWORTH, TRUSTEE, OF BROOKLINE, MASSACHUSETTS.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent. Patgnted D1 30, 1920,

Original application filed July 25, 1917, Serial No. 182,609. Divided and this application filed June 27, 1918. Serial No. 242,320.

To all whom it may concern:

Be it known that I, FRED HENRY GILE, a citizen of the United States, and a resident of Cliftondale, in the county of Essex and State of Massachusetts, have invented a new and useful Improvement in Internal-Combustion Engines, of which the following is a specification.

My invention relates to internal combustion engines and its objects are to improve and simplify the construction thereof and increase the efficiency of the same in the manner hereinafter set forth.

In an earlier application (Serial No. 19,265, filed April 5, 1915) I have disclosed means for effecting a substantially complete combustion of the charge of fuel and air, said means comprising a relatively large number of fuel passages through which the charge is forced under pressure to the combustion chamber thereby thoroughly, intimately and completely mixing the same. I have discovered that it is not necessary to subdivide the charge in the manner set forth in said application in order to effect perfect mixing and complete combustion, and that these results can be accomplished by forcing the charge under pressure into the combustion chamber in the form of a thin cylindrical or annular sheet instead of a number of small streams.

In the present application, which is a division of my application Serial No. 182,-.

609, filed July 25, 1917, I show and claim an engine having a cylinder of uniform diameter wherein the fuel charge is drawn into the space between the power piston and the sub-piston on one stroke and forced into the combustion chamber around the head of the sub-piston in a thin cylindrical or annular sheet on the other stroke.

The accompanying drawings show one embodiment of the present invention but it is to be understood that various modifications may be made therein and various other arrangements devised for forcing the charge into the combustion chamber in the form of a thin cylindrical sheet withoutdeparting from the scope of my invention as defined by the appended claims.

In the drawings- Figure 1 is a central vertical section of an engine einbodying my invention. Fig.

2 is a section taken on the line 22 of Fig. 1. Fig. 3 is a plan view of the cylinder with the head removed.

In the particular drawings selected for more fully disclosing my invention 1 is a cvlinder suitably secured to the crank caslng and the upper end thereof is counterbored at 2, the bottom of said counterbore preferably being beveled inwardly. Arranged to reciprocate within the cylinder is a power piston 3, and the two-part pitman 41 engaging the pin 5 secured in the walls thereof, connects the same to the crank 6. A sub-piston 7 is arranged to reciprocate within the cylinder between the power piston and the combustion chamber and its rod 8' passes through and is guided by the central core of the power piston, its lower end being pivotally connected to the double link 9 which in turn engages the arm 10 of the rock shaft 11 journaled in the sides of the frame and passing across the latter above the crank shaft and to the rear thereof.

A rod 12 connects the shorter arm 13 on said rock shaft with the arm 14 integral with the rock shaft 15 which is journaled between the frame and the block 16 which rises from the base thereof. The hub 17 of the connecting rod 18 is in engagement with the wrist pin of the crank 6, being arranged between one arm of said crank and the box of the pitman 4, and said rod is pivotally connected with the longer arm 19 of the rock shaft 15. The sub-piston therefore is controlled positively throughout the entire cycle.

The cylinder has an exhaust passage 20 controlled by the valve 21 normally held to its seat bv the spring 22 which surrounds the valve stem 23 and bears against the valve housing and the collar 24 on said stem. The valve may be opened by any suitable mechanism such for example as the tappet 25 actuated by the cam 26 which 00- operates with the head 27 thereof.

The fuel inlet 28 is located a short distance above the lower end of the power piston when the power piston is in explosion position at the end of its upstroke as shown in Fig. 2.

In this construction it is essential that there should be a gas-tightjoint between the sub-piston and the cylinder, and to this end the sub-piston is provided with the usual piston ring 29.

In order to prevent the ring from springing out of its groove when the sub-piston projects into the counterbored end of the cylinder I provide as shown an undercut ring 30 which may be screwed to the upper face of the subiston and the depending outer edge of w iich engages the rabbeted portion of the piston ring. It Wlll be obvious that various other equivalent means may be devised for holding the ring in osition without destroying its freedom of movement which is essential to the performance of its function.

I do not limit myself as to the depth of the counterbore 2 or to the area between the peripheral surface of the sub-piston and the wall of the counterbored portion of the cylinder,in other words, to the thickness of the cylindrical sheet in which the charge passes to the combustion chamber. It must be sufficiently thin to effect such a thorough mixing of the charge that substantially complete combustion will result on ignition. If it is too thin, the back pressure will be excessive. If it is too thick the mixing will not be thorough and the resulting colnbusr tion will not be complete or substantially complete. No hard and fast rule can be given as to the depth of said counterbore which will give the best results under all conditions of operation and for all kinds of fuel. I have found however that in a cylinder having a four inch bore and a five inch stroke, the counterbore 2 may be onesixty-fourth of an inch, two-sixty-fourths of an inch, three-sixty-fourths of an inch, or founsixty-fourths of an inch. I believe that good results could be obtained in such cylinder if the counterbore exceeded in depth four-sixty-fourths of an inch. I have found that in the engine above referred to the best results were obtained with a-eounterbore three-sixty-fourths of an inch deep. In that case the area inclosed between the wall of the counterbored portion of the cyl inder and the periphery of the sub-piston was almost exactly equal to one-half of the area of the intake port. I believe therefore that this area depends in a way upon the volume of the cylinder and upon the cross sectional area of the intake port. I believe also that this area must be such, due re gard being had to the cubical contents of the cylinder and the cross sectional area of the intake port, that sufficient restraint will be imposed to the passage of the gas through the counterbore as to enable the same to acquire a relatively high velocity during such passage.

As shown, the bottom of the counterbore preferably is beveled inwardly so as to prevent undue heating of the square corner that would exist were the bottom of the counterbore at right angles to the wall thereof,

The operation is as follows: When the pistons are at the upper end of their strokes (ex losion position) as shown in Figs. 1 and 2, tie charge is fired and both pistons demoves away therefrom until the crank hasarrived at about 135 from its explosion position. The sub-piston is then at the lower end of its stroke with its upper face just above the fuel inlet 28 and the upper face of the power piston is just below said inlet. Further rotation of the crank causes the power piston to continue its down-stroke and the sub-piston to begin its upstroke. The relative movement between the pistons creates a vacuum in the space between them into which a charge of fuel is drawn through theinlet 28. The exhaust valve 21 opens practically simultaneously with or prefer ably shortly before the commencement of the upstroke of the sub-piston and the burnt gases of the preceding explosion are expelled by the latter, which thereby prevents the admixture of the next charge with said burned gases. When the crank has arrived at about 240 from initial position the subpiston has reached explosion position and from this point until the crank returns to initial position and the power piston assumes the position shown in Fig. 2 the sub-piston remains substantially stationary. As soon as the power piston onits upward stroke covers the fuel inlet, it begins to compress the charge in the space between the pistons,

and a portion of the charge so compressed passes around the head of the sub-piston through the counterbored end of the cylinder to the combustion chamber thereby assisting the scavenging of the latter before the exhaust valve closes. The'power piston continuing its upward stroke further compresses the charge and expels the same from the space between the pistons through the space between the sub-piston and the counterbored end of the cylinder into the combustion chamber thereby thoroughly mixing the same. When the parts have again assumed the position shown in Fig. 2 the entire charge has been forced into the combustion chamber in the form of a thin cylindrical or annular sheet whereupon ignition occurs and the cycle is repeated.

It will be noted that the compression of the charge is continuous and increases 'progressively until the power piston. reaches the end of its stroke, and that the charge is not permitted to expand after having reached its maximum pressure until it is fired.

It will be obvious that by duplicating the sub-piston control apparatus shown in igs. 1 and 2, i. 6., the system of links and rockshafts which govern the movement of the sub-piston to which apparatus I make no claim, my invention may be applied to a double acting engine having two sub-pistons, one on either side of the power piston.

I claim:

1. An internal combustion engine, comprising in combination a cylinder, a powerpiston and a sub-piston both arranged to reciprocate therein, the combustion-chamber end of said cylinder being counterbored, a rabbeted ring in a groove in the peripheral surface of said sub-piston, and an undercut ring secured to the upper face of said subpiston and having its depending outer edge in engagement with the rabbeted portion of said ring. I

2. An internal combustion engine, comprising in combination a cylinder, apowerpiston and a sub-pistonboth arranged to reciprocate therein, the combustion-chamber end of said cylinder being counterbored, a rabbeted ring in a groove in the peripheral surface of said sub-piston, and means secured to said sub-piston for preventing said ring from springing out of its groove.

3. An internal combustion engine, comprising in combination a cylinder, a powerpiston and a sub-piston both arranged to reciprocate therein, the combustion-chamber end of said cylinder being counterbored, a ring in a groove in the peripheral surface of said sub-piston, and means for maintaining said ring in its groove.

4. An internal combustion engine, comprising in combination a cylinder having a combustion chamber, means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced under pressure into said combustion chamber in the form of a hollow cylinder, the walls of which are sufficiently thin to effect such a thorough mixing of said charge that substantially complete combustion will result on ignition, a valveless sub-piston for preventing said charge from commingling with the burned gases of the previous explosion and means for controlling said subpiston positively throughout the entire cycle.

5. An internal combustion engine, comprising in combination a cylinder having a combustion chamber, means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced under pressure into said combustion chamber in a thin annular sheet, a valveless sub-piston for preventing said charge from commingling with the burned gases of the 5 previous explosion and means for controlling said sub-piston positively throughout the entire cycle.

6. An internal combustion engine, comprising in combination a cylinder having a combustion chamber, means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced under pressure into said combustion chamber in an annular sheet sufliciently thin to effect such a thorough mixing of said charge that substantially complete combustion will result on ignition, a valveless sub-piston for preventing said charge from commingling with the burned gases of the previous explosion and means for controlling said sub-piston positively throughout the entire cycle.

7. An internal combustion engine, comprising in combination a cylinder terminat-v ing in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a sub-piston located between said power piston and said combustion chamber, the area between the peripheral surface of said sub-piston and the wall of the counterbored portion of the cylinder being so small that a charge of fuel and air may be forced therethrough into the combustion chamber in an annular sheet sufficiently thin to effect such a thorough mixing of said charge that substantially complete combustion will result on ignition, and means for controlling said sub-piston positively throughout the entire cycle.

8. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a sub-piston located between said power piston and said combustion chamber, and means for controlling said sub-piston positively throughout the entire cycle. 1

9. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a subpiston located between said power piston and said combustion chamber, a shaft hav-' ing a crank, a pitman connecting said power piston to said crank, and means actuated directly by said crank for controlling said sub-piston positively throughout the entire cycle.

10. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a sub-piston located between said power piston and said combustion chamber the area between the peripheral surface of the sub-piston and the wall of the counterbored portlon of the cylinder being so small that a charge of fuel and air may be forced therethrough into the combustion chamber in a cylindrical sheet sufficiently thin to effect such a thorough mixin of such charge that substantially comp ete combustion will result on ignition, and means for controlling said sub-piston positively throughout the entire 0 cle.

11. An internal combustion engine, comprising in combination a c linder terminating in a combustion cham er, a power plston arranged to reciprocate in said cylinder a valveless sub-pisto'nlocated between said power piston and said combustion chamber, the area between the peripheral surface of said sub-piston and the wall of the cylinder at the combustion-chamber end thereof being so small that a charge of fuel and air may be forced therethrough into the combustion chamber in an annular sheet sufficiently thin to effect such a thorough mixing of such charge that substantially complete combustion Will result on ignition, and

means for controlling said sub-piston positively throughout the entire cycle:

12. An internal combustion engine, comprising in combination a cylinder having a combustion chamber, a power piston arranged to reciprocate in said cylinder, a valveless sub-piston arranged between said power piston and said combustion chamber, said sub-piston constituting means whereby a charge of fuel and air is drawn into said cylinder and also means for preventing said charge from commingling with the burned gases of the previous explosion, means whereby said charge is forced under pressure into said combustion chamber in an annular sheet sufficiently thin to effect such a thorough mixing of said charge that substantially complete combustion will result on ignition, and means for controlling said sub-piston positively throughout the entire cycle.

13. An internal combustion engine, comprising in combination a cylinder having a combustion chamber, a power piston arranged to reciprocate in said cylinder, a

- valveless sub-piston arranged between said power piston and said combustion chamber, said sub-piston constituting means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced continuously and with progressively increasing pressure into said combustion chamber in an annular sheet sufficiently thin to effect such a thorough mixing of said charge that substantially complete combustion will result on ignition, and means for controlling said sub-piston positively throughout the entire cycle.

14. An internal combustion engine, comprising in combination a cylinder terminatmg in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power iston arranged to reciprocate in said cylin er, a sub-piston located between said power piston and said combustion chamber, a ring in a groove in the peripheral surface of said sub-piston means for maintaining said rin in said groove the area between the perip eral surface of said sub-piston and the wall of the counterbored portion of the cylinder being so small that a charge of' fuel and air may be forced therethrough into the combustion chamber in an annular sheet sufficiently thin to effect such a thorough mixing of said charge that substantially complete combustion will result on ignition, and means for controlling said sub-piston.

15. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a sub-piston located between said power piston and said combustion chamber, a ring in a groove in the peripheral surface of said sub-piston, means for maintaining said ring in said groove, and means for controlling said subpiston.

16. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a sub-piston located between said power piston and said combustion chamber, a ring in a groove in the peripheral surface of said sub-piston, means for maintaining said ring in said groove, a shaft having a crank, a pitman connecting said power piston to said crank, and means actuated directly by said crank for controlling said sub-piston positively throughout the entire cycle.

17. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being counterbored, a power piston arranged to reciprocate in said cylinder, a sub-piston located between said power piston and said combustion chamber. a ring in a groove in the peripheral surface of said sub-piston, means for maintaining said ring in said groove, and means for controlling said subpiston positively throughout the entire cycle.

18. An internal combustion engine. comprising in combination a cylinder of uniform diamet r having a combustion chamber. means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced under pressure into the combustion chamber in the form of a hollow cylinder, the walls of which are sufliciently thin to efi'ectsuch a thorough mixing of said charge that substantially complete combustion will result on ignition, a valveless subpiston for preventing said charge from commingling with the burned gases of the revious explosion, and means for control ing said sub-piston.

19. An internal combustion engine, comprising in combination a cylinder of uniform diameter having a combustion cham-) ber, means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced under pressure into said combustion-chamber in a thin annular sheet, a valveless sub-piston for preventing said charge from commingling with the burned gases of the previous explosion, and means for controlling said sub-piston.

20. An internal combustion engine, comprising in combination a cylinder of uniform diameter having a combustion chamcounterbored, a power ber, means whereby a charge of fuel and air is drawn into said cylinder, means whereby said charge is forced under pressure into said combustion chamber in an annular sheet sufficiently thin to effect such a. thorough mixing of said charge that substantially complete combustion will result on ignition, a valveless sub-piston for preventing said charge from commingling with the burned gases of the previous explosion, and means for controlling said sub-piston.

21. An internal combustion engine, comprising in combination a cylinder terminating in a combustion chamber, the combustion-chamber end of said cylinder being iston arranged to reciprocate in said cylin er, a sub-pistonlocated between said power piston and said combustion chamber, and means for positively controlling said sub-piston.

In testimony whereof I have hereunto subscribed my name this 10th day of May, 1918.

FRED HENRY GILE. 

